System of distribution.



E. 0. SCHWEITZiR.

SYSTEM OF DISTRIBUTION.

APPLICATION FILED AuG.28'.' 1914.

1,162,405v Patented N0v. 30, 1915.

2 SHEETS-SHEET I.

w/i/tmasse 6 16 lnusrv fw I H 1 M m vii/$246 i I I. y fiat/11 26595 0 E.O. SCHWEITZER. SYSTEM OFDISTRIBUTION. v APPLICATKQN men AUG.2'B. 1914.

1 Ja -A05, Patented Nov. 30,1915.

2" SHEETSSHEET 2.

EDMUND O. SCHWEITZER, OF CHICAGO, ILLINQIS.

sYsrnM or DISTRIBUTION.

Specification of Letters Patent.

Patented Nov. 36, 1915.

Application filed August 28, 1914. Serial No. 859,038.

To all whom it may concern:

Be it known that I, EDMUND O. Scrnvmrzan, a citizen of the UnitedStates, and resident of Chicago, in the county of Cook and Statc ofIllinois, have invented certain new and useful Improvement in Sys--.

toms of Distribution, of which the following is a full, clear, and exactdescription, reference being had to the accompanying drawings, forming apartof this specification.

The subject-i'natter of this invention is a system of distribution.

In my copending application, Serial No. 852,629, filed July 23, 191%, Ihave described a system of distribution in which it is possible to feedfrom the same transformer one branch circuit containing electric lamps,or other devices which require a fairly steady voltage, and anotherbranch or branches including a variable voltage device such as aninduction motor. The abovedescribed sys; tem is eminently satisfactoryfor a fixed lamp load regardless of the variations of current taken bythe motor load, but compensation becomes imperfect when the lamp loaditself is varied.

It is the object of the present invention to provide a system ofdistribution for feeding from a given source of power loads of differentcharacteristics, one of which shall consist of constant voltage devices,the carrying mains for which loads are so related as to maintain aconstant voltage upon the constant-voltage devices under all reasonablevariations of the amount of current drawn by either or both loads. I

In the accompanying drawingsFigure illustrates a system of distributionembodying the principles of my invention; Fig. 2 is a diagram of amodified system; and Fig. 3 is a diagram of a further modification.

In the system shown in Fig. 1, it is pro posed to supply current fronratransformer 1,-having the primary or line winding 2 and the secondary orfeeder winding 3, to an induction motor 4, or other variable currentdevice, and to lamps 5 or other constantvoltage devices. It iswell-known that the induction motor can be operated upon varyingvoltages as the only effect of a lower voltage will" be a deer aseinspeed. The characteristics of electric lamps, especially of theincandescent types, is such that any considerable variation in voltageis not permissible. If the voltage is lowered, the illuminating" poweris very greatly de creased and, if the voltage is increased, the

life of the lamp is unfavorably affected. The secondary winding' of thetransformer l is connected through a compensating transformer (5 to thevarious loads in such a manner that all the constant-voltage devices arefed in series through one winding 7 of this transformer and all thevariable-current devices 4 are connected-in series with the' winding 8of the compensating transformer. The relation of the windings 8 and "7is such that an increase of current through the variable-ciirrentdevices will cause sufficient additional voltage to be generated in thewinding 7 to compensate for the IR and IX drops in the winding of themain transformer. By providing a suitable shunt 9 around the winding 7,I am enabled to obtain a suitable characteristic for the compensatingtransformer, so that the effective voltage induced in the winding 7 isnot only substantially proportional to the amount of current flowing inthe winding 8 in series'with the variable current devices l, but is alsocorrect in amount to compensate for the IR and 1X drops. If the ratio ofthe effective voltage induced in winding 7 is in proportion to thecurrent flowing in the winding 8, then, it can be seen that forsubstantially all values of current in the motor circuit duecompensation can be secured in the lamp circuit. The shunt 9 is providedwith resistance 10 and inductance 11, which may be cut out of circuit bymeans of a slider 1'2, or other switching arrangement. The proportion ofcurrent flowing through the winding 8 may also be adjusted by means of ashunt 13, containing resistance l t and inductance 15. The relativeamounts of resistance andinductance included in circuit may be con.trolled by slider 16.

The arrangement so far described can be adjusted accurately for allvariations of current through the motor circuit with a given lamp loadin the lamp circuit, that is, compensation may be practically perfect,but inherent regulation of the lamp circuit will be poor. This isbecause any excess current flowing in the lamp circuit will tend toboost the voltage in the motor circuit, this having a deterimentaleffect upon the lamp voltage. It is, therefore, desirable to introducesome element, or a number ofelements, which will allow a return of themotor circuit by increased current in the lamp circuit, or which willindependently transfer energy from the motor circuit to the lampcircuit. It can be seen that if the effect of preventing a transfer ofenergy could be accomplished, the inherent regulation in the lampcircuit would be improved.

I.have illustrated in the figures one general scheme for preventing at'ansfer of energy from the lamp circuit to the motor circuit uponincrease of current in the lamp circuit. It is to be understood that thescheme that I have proposed is not the only possible means, as I haveillustrated this particular embodiment of the invention only for thepurpose of complying with the statutes. and any means which will producethe results of improving the inherent regulation of the lamp circuit,either by return ing part of the energy which is transferred to themotor circuit, or by preventing its transference. comes broadly withinthe spirit and scope of my invention. In Fig. 1, the means shown foraccomplishing this general purpose is the closed circuit 17, includingthe windings 18 and 19. The winding 18 is wound closely over the winding17, which, in turn, is wound upon the limb 20 of the transformer core.The winding 19 is wound over the winding 8, which is wound upon the limb21 of the transformer core. I have shown the core 6 of the transformeras comprising an open magnetic circuit.

This is for the purpose of allowing the circuit 17 to operate in themanner above de scribed. as-leakage in thetransformer between thewindings 7 and 8 is essential to the proper operation of the device. Thewinding 18 may be shunted by a circuit 22 controlled by a slider 23. Thewinding 19 may also be so adjusted. if desired. The windings 7 and 18are so disposed that very little magnetic leakage between these twowindings is possible. In the same manner, the windings 8 and 19 areclosely related in order that a substantially exact ratio between thevoltages of these windings shall obtain. In effect. increase of currentwould tend to transfer energy through the iron core of the transformerto the motor circuit, but suflicient current circulates through thecircuit 17 to return such increase to the lamp circuit. In substance.the above are the tendencies. although the operation of the device maybe simply such as to prevent such transfer of energy. only sullicientcurrent circulating through the circuit 17 to maintain the properrelation betwecn the two load circuits. The purpose of the closedcircuit including the wingings l8 and l.) is to improve thellalacterisiics of the lamp circuit indepcinlcntly ol' the. motorcircuit. This is accomplished by the short circuit effect caused by thecombined action of the magnetic circuit and the closed electriccirspective currents flowing through the motor and through the lamp. Byvarying the number of turns to obtain the required degree of asymmetryproper cinnpensation can be secured. The system shown in Fig. 2 issubstantially the same as that shown in Fig. 1 with the exception that Ihave shown a transformer having a closed nuignetic circuit. The iron isso arranged as to allow of a fairly large magnetic leakage in order toproduce the effect described in connection with Fig. 1. In otherrespects, the sys tem is substantially the same. I

In the system shown in Fig. 3, I have indicated a transformer 26 havingan open magnetic circuit and means for varying the magnetic leakage. Thecore is made up of E-shaped stampings, having a central part 27, uponwhich the transformer wind= ings are plat-u. and outer portions 28. 29forming the return paths for the lines of force. A pivoted bar 30.having means 31 for varying its distance from the cores 27, 28, '29,forms an adjusting means for varying the leakage of the transformer. Thecircuit 17 is arranged to include a greater or less number of turns ofthe windings 18 and 1!) by providing suitable laps in these windingsarranged to be connected in circuit by sliders rl. 33. or similarswitching arrangements. The amount of resistance and inductance in thecircuit may also be controlled by means of a sliding switch arrangement34.

The operation of the system is as follows: Upon the connection of themotor r. with the secondary of the transformer. by closing the. switchin the motor controller 35, cur rent will flow from the secondary of themain transformer through the winding 8 of the compensating transformer.the motor 4 and controller 35. and back over the line 24. If no lampsare included in the lamp circuit, the winding 9 will olTer merely aslightly larger impedance and resistance to the flow of current thanifthe same were not in circuit. A certain amount of current will tend tocir 'ulate in the circuit 17. but this is of minor importance inasmuchas the speed of the motor i does not need to be constant or even of adefinite value. lf the lamps 5 wer connected in the. lamp circuit; atthe time that the motor is started. then. there. would be a tendency forthe additional current drawn by the motor from the secondary winding Iiof the main transformer to lamps will occur.

-nals through the action of the windings mounted on the transformercore. In this manner, not only can the variations of voltage" upon thelamp terminals be greatly compensated for, but the inherent regulationof the circuit can thus be improved to such an extent that forsubstantially all loads in the motor circuit 4: and for substantiallyall loads in the lamp circuit, no objectionable variation in voltageimpressed upon the It is understood, of c0urse,'that the characteristicsoi compensation and regulation are contradictory and the most successfularrangement will be. a compromise between the two.

It will be apparent at once that the prob lem which I have solved in theabove system of regulation is capable of a great number or solutions,using, instead of the exact elements that I have shown, numerousvariations and substitutions.

In using the above-described system to supply current to a three-wireservice sys tom, the motor circuitmaybe connected across the outer wiresand the lamps between theneutral illldlll'lt outer wires. In such case,the values for compensation and regulation will be accordingly reducedby about one-half. It is also to be noticed that the invention abovedescribed is not to. be limited to systems including only motors orlamps, but broadly to all systems including constant-voltage andvariable-voltage devices. In the following claims I employ -;.the termsconstant voltage (le\'iees -and variable voltage devices to designatedifferent types of apparatus. These terms are not used in their absolutesense but in a 'relativv sense in order to entitle the claims to thebroadest interpretation, which they are warranted in-viewof the priorart. T ie circuit 17 may also be employed in' improving thecharacteristics of the ordinary potential transformer used in powerservice.

I consider the above-described system of distribution to be"broadly newand desire that the appended claims be construed as broadly as possible.,VVhat I claim is the following: 7

- 1. In a system of distribution, a source of electro-motive force, aconstant voltage current operated device connected to said source, avariable voltage device connected to said source, and means operated bythe current taken by said variable voltage device to impress a separatevoltage upon said constant voltage device to, transfer energy thereto,said means preventing the return of energy from said constant voltagedevice to said variable voltage device.

In a system of the class described, a source oi elr-ctro-motive force, aconstant voltage device, a variable voltage device, means operated bythe current taken by said variable voltage device to impress anadditional electro-motivc force upon said constant voltage device andmeans for re ducing the voltage drop of said means when the variablevoltage device is disconnected.

3. In a system oi the class described, a source oi? electio-motiveforce, a constant voltage load device, a variable voltage load device,means operated by current taken by said variable voltage load device toimpress an additional electromotive force upon said constant voltagedevice, said means having windings in series with the load devices andmeans for reducing the influence of each winding when the otherdiscoiuiccted.

In a sv tcm of distribution, a source of electro-inotive force, aconstant voltage device. means connecting said constant voltage levicewith said source of clocti'o-niotivc force, a variable voltage device,means connecting said variable voltage device to said source ofclectro-inotive force, a connection between the mains oi said variablevoltage device, and said constant voltage device, said connection beingasymmetric for allowing energy to be transferred from the circuit ofsaid variable voltage devicebut substantially preventing encrgv frombeing transferred from the circuit of said constant voltage device tosaid variable voltage'device.

The method of voltage, compensation I and regulation of one branch of asplit load circuit, which consists in impressing a commonclecti'o-motive force upon the load circuit: coii ointly therewithimpressing. an

clcctro-motive force upon one branch of the load circuit, substantiallyin phase with the common electro-inotive force, and substantially inproportion to the amount of current drawn in another branch andsii'nultane-,

ouslv generating two electro-motive forces, by the action o'f'thecurrents Flowing in said one branch of said transformer circuit in accordance with the current drawn in another branch of the transformerclrcuit', 1n generating opposing electro-motive forces by the.

current in each of said transformer circuits, and causing one of saidvoltages to overpower the other in order to transfer energy from onecircuit to the other.

7. The method of distributing and regulating alternating current among aplurality of branch load circuits which consists in impressing a commonelectromotive force on all of said circuits-causing a current flow ineach circuit-each current generating magnetic lines of force opposingeach other-gencrating unequal electromotive forces by each of saidopposing magnetic lines-and causing the resultant current flow totransfer energy to one of said branch load circuits.

8. The method of maintaining a uniform pressure upon a lamp load fedfrom a transformer in pa 'allel with a motor load which consists inimpressing a common electromotive force upon both loadscausing separatecurrents to flow to the lamp and to the motorcausing the moto' and lampcurrents to set up opposing magnetic fiuxes-gencrating unequal voltagesby said fluxes-and causing the resultant current flow to-induce aseparate electromotive force in the lamp circuit.

9. In combination, a source of singlephase alternating current. a loadconnected thereto, a winding in series with said load, a core for saidwinding, a second winding connected to said source independently of saidfirst winding, an auxiliary winding embracing said first winding andenergized thereby, a second auxiliary winding embracing said secondwinding and energized thereby, said auxiliary windings being connectedtogether in opposition and being independent of said other windings.

10. In combination, a core, a pair of auxiliary windings thereupon,-saidwindings having their terminals connected together, a source of current,a load, a winding in series with said load and said source, said windingbeing disposed in close inductive relation to one of said auxiliarywindings but' electrically independent of said winding. a second loadand a second winding in series with said second load and said sourcesaid second winding being disposed in close. inductive relation to theother of said auxiliary windings, said auxiliary windmgs being energizedin opposition by a current in said load winding.

ll. A load circuit having a plurality of branches, a common source ofcurrent for said branch loads, a transformer having a pair of windings.a winding of said pair being connected in series relation to one ot saidbranch-10ml circuits, said windings when energized energizing the corein oppo site directions, an auxiliary winding dis- 12 In a system of theclass describcd, a winding, means to generate in said winding anelectrom'otive torce,' a circuit connected to said wlndmg, a pluralityof branch circuits connected, to said circuit, means 1n one of saidbranch circuits for.

creating an independent eleetromotive force in another one of saidbranchicircuits, and V a closed circuit inductively relate'dfto both ofsaid branch circuits.

13. A system of the class described, a

winding, means to generate in said winding,

an electromotive force, a circuit connected to said winding, a pluralityof branch circuitsconnected to said circuit, means in each of saidbranch circuits for influencing the voltage of the remaining branchcircuits, and means for preventing the transfer of energy from one ofsaid influenced circuits to the influencing circuit.

14. In a system of the class described, a

winding, means to generate therein an electromotive force, a clrcu tconnected to said winding, a branch circuit connected to said circuit,said branch including a variable voltage load and a windlng m'seriestherewith, a second branch circuit connected to said circuit, saidsecond branch including a constant voltage load, and a winding in se-,ries therewith, an iron core connecting said windings, and a closedcircuit having windings in close inductive relation to the windings of.said b 'anch circuit said closed circuit windings being disposed onsaid core and energized simultaneously in opposite directions.

15. In a'system of the class described. common feeder mains, a pair ofbranch load circuits connected to said mains, a magnetic core, means ineach of "said branch circuits inductively related to said core, means ineach circuit for varying the amount of current flowing in thecorresponding circuit, and a closed circuithaving a pair of Windings ininductive relation to said magnetic cor; each of said pair ofwindingsbeing individual to one of said branch load circuits.

16. In a system of the class described, common feeder mains, a pair ofbranch load circuits connected to said mains, a magnetic core. windingsin each of said branch circuits inductively related to said core. meansin said circuit for varying the amount of current flowing in saidcircuit. and a pair of separate windings on said magnetic core ininductive relation to said branch circuits,

said separate windings being connected directly together in a closedcircuit and ener-- gized in, opposition by the windings in saidbranch-load circuits.

17. In combination, a transformer core, a pair of windings disposed onsaid core to permit of relatively high magnetic leakage between saidwindings, another pair of windings disposed on said core in closeinductive relation to said first pair ofwindings, said second windingsbeing independent electrically of said first pair of windings andconnected together in opposition, and means to impress a common singlephase alternating elcctromotive force upon said first pair of windingssimultaneously to energize the sanie.

18. In combination, a core having two limbs, a source of single-phasealternating current, a winding on one limb connected in series with saidsource of current, a second winding on the other limb, a load connectedto said second winding, an auxiliary winding in close inductive relationwith said first winding, another auxiliary winding in close inductiverelation tosaid second winding, said auxiliary windings being at alltimes independent of said windings and being connected directly togetherin a closed circuit.

19.111 combination a core having two limbs, av winding on one limb, asource of single-phase alternating current supply for said winding, anindependent winding on said second. limb, said second winding beingconnected to the same source of current supply in parallel relation tosaid first winding, auxiliary windings for eachof said limbs, saidauxiliary windings being independent of said windings and beingco-nnected together in opposition.

2O.In.co1nbination a core having two limbs, a winding on one limb, a.source of current supply connected to said winding, a winding on saidother limb, said second winding being adapted to be connected to a loaddevice, auxiliary windings for each of said limbs, said auxiliarywindings being connected together in opposition, one ot'said auxiliarywindings comprising number of turns than the other.-

21. In combination a core having two limbs, a winding on one limb, asource of current supply connected to said winding, a winding on saidother limb, said second a greater Winding being adapted to be connectedto a.-

i said, cor), a working circuit connected to said second winding,auxiliary windings electrically independent of said windings in closeinductive relation to each of said windings, said auxiliary windingscomprising an unequal number of effective turns and being connectedtogether in opposition in a constantly-closed circuit.

r 23 In combination av core, a winding on said core, a. working circuitconnected in series with said winding, a. second winding on said core, aseparate working circuit connected in series with said second winding, acommon source of single pliasc current supply connected. to saidwindings, auxiliary windings in close inductive relation to each of saidwindings, said auxiliary windings being connected together in oppositionand means to vary the elfective number of turns of the windings.

2%. In combination a core, a winding upon said core, a source of currentconnected to said winding, a second core, an independent winding uponsaid second core, a load circuit connected to said second winding, anauxiliary winding upon said first core, an

auxiliary winding upon said second core, said auxiliary windingscomprising an unequal number of effective turns being connected directlytogether in opposition and means to vary the effective number of turnsof the windings, said auxiliary windings being independent of said otherwindings.

25. In combination a common source of singlepliasc alternating current,:rdoud, a winding in series with said source and said load, a. secondload, a second winding inductively related to said first winding andbeing in series with said common source and said second load anda pairof windings in close inductive relation to said first and said secondwindings respectively, said pair of windings being connected together inseries and being energized substantially simultaneously in opposition.

26. In combiimtion, a core having two limbs, a winding on one limb, a.source of current supply connected to said winding, a winding on saidother limb, said second winding being adapted to be connected to a loaddevice, auxiliary windings for each of said limbs, said auxiliarywindings being connected together in opposition, and a resistanceshunted across said first winding.

27. in combination, a core having two limbs. a winding on one limb, asource of current supply connected to said winding, a winding on saidother limb, said second winding being adapted to be connected to a loaddevice, auxiliary windings for each of said limbs, said windings beingunequaled in effective number ol turns and being connected together inopposition, and a. regulatlug, shunt across said first winding.

2S. Incou1l inati m,a corclmvingtwolimbs, a winding on one limb, asource of current supply connected to said winding, a wind- Winding onsaid other limb, Said second Winding being adapted to be OnnQ tsd to aoa ce, aux l a y w ndings for each of said limbs, said windings beiiiunequal in effective number of turns an being conpe ted t g th r inopposition, and a regulatmg shunt connected across one of said auxiharywindings.

30., In combination, a core having two limbs, a Winding on-one limb, aregulating shunt connected across said winding, a source of currentsupply connected to said Winding, a winding on said other limb, saidsecond winding being adapted to be connected to a load'device, auxiliarywindings forea'ch of said limbs, said auxiliary Windings being connectedtogether in opposition, and a regulating shunt for one of said auxiliarywindings.

In Witness whereof, I hereunto subscribe my name this 27th day ofAugust, AJD.

EDMUND O. SCHWEITZER. lVitnesses:

LEONARD V. NOVANDER, CAMERON A. WHITsETT.

